Romanian Navy Blasts Danube Riverbed as Cernavoda Shutdown Drives SE Europe Nuclear Cuts Toward 48%
Record-low Danube levels forced Romania to shut its last operating reactor on August 13, with regional nuclear unavailability approaching half of installed capacity.
Romania's navy carried out controlled explosions in the Danube riverbed to try to improve water flow to the Cernavoda nuclear plant, a measure that captures how severe the region's drought-driven power shortage had become.5 Nuclearelectrica on Thursday (2026-08-13) began shutting down Cernavoda's only remaining operating reactor, a 680 MW unit, after Danube levels fell to a 90-year low, OilPrice.com reported.6
With both of Cernavoda's units now offline, Romania's entire 1.35 GW nuclear fleet went dark. Southeast Europe's share of nuclear capacity unavailable owing to cooling constraints approached 48%, Montel reported, up from 37% before the final reactor shutdown. The region had already seen unavailability breach 42% earlier in the crisis before a brief period of relief reversed.4
The drought driving the outages has been accumulating in record terms since late July. On Tuesday (2026-07-28), Hungary's water managers recorded a Danube level of 31 centimetres at Budapest, shattering the previous all-time low of 33 centimetres set on October 25, 2018, according to TechTimes citing Hungarian authorities.7 Hydroelectric output was also falling across the region, adding to a generation shortfall that nuclear curtailments were already widening, OilPrice.com reported.1
Hungary faced the same constraints at national scale first. Paks, the country's 2 GW nuclear plant generating close to half its electricity, was curtailed to just 0.24 GW, Montel reported. Water levels stopped falling before a complete Paks shutdown became necessary, according to irinaslav.substack.com reporting, though the plant had already been reduced to a small fraction of rated capacity. Prime Minister Péter Magyar warned of a full energy crisis, and the European Commission signalled it was prepared to convene an emergency meeting of its Electricity Coordination Group, Euronews reported.3,2,8
By Monday (2026-08-10), conditions appeared to be stabilising. Regional nuclear unavailability fell to 35% from 42%, Montel reported, with Paks beginning to ramp from 0.24 GW to 0.72 GW that night and water levels at Cernavoda rising roughly 80 millimetres. Nuclearelectrica said the improvement could sustain operations for at least nine more days.3
But the stabilisation did not hold. Three days later, on Thursday (2026-08-13), Cernavoda's shutdown began as the Danube remained at record lows. The Romanian Navy's riverbed blasts, timed around the same period, illustrate how little margin remained between the plant's cooling requirements and what the river could supply.6,5
Standard Chartered commodity analysts noted that extreme heat and drought were simultaneously affecting refinery cooling efficiency, nuclear generation, hydroelectric output, and inland barge freight — a broader set of impacts than seasonal temperature swings typically deliver, OilPrice.com reported.1
Romanian day-ahead power settled at €126.00 per megawatt-hour on Sunday (2026-08-16). German power stood at €134.87 per megawatt-hour on the same date.
The pace of any Danube recovery at Cernavoda is what the regional power market is now tracking. The August 10 (2026-08-10) water-level improvement was enough for Nuclearelectrica to project nine more days of continued operation — yet the plant shut three days later. With the river already at a 90-year low and no rainfall data in current reporting to indicate an imminent turnaround, the date on which Romania's 680 MW reactor re-enters service remains the central uncertainty for the region's power balance. The navy's riverbed explosions are the most concrete evidence of how far operators pushed conventional emergency measures to maintain cooling.3,6,5